A substantial percentage of the mattresses produced in the United States today, and an even larger percentage of the cushions and paddings utilized in the furniture industry are constructed from flexible foam materials. The manufacturers of these foam products have invested large sums of money and time in research to improve the quality and performance of their products and have had considerable success in controlling such characteristics as firmness values, densities, life expectancy etc. of the mattresses and cushions which reach the consumer. For example see U.S. Pat. No. 3,939,508 to Hall et al.
Because of the nature of the foam materials used in this industry, however, there remains a problem with maintaining the conformation and structural quality of the edges and corners of the cushions and mattresses. The term "rollover" is commonly used in the industry to define a deformed condition caused by a permanent collapse or sagging of the edges and corners of cushions which frequently occurs after a period of use. Such collapse or "rollover" usually increases with age and use of the product and is both unsightly and uncomfortable to sit or lie upon. When edge collapse occurs on upholstered furniture cushions, it will create extra wear on upholstery fabrics and cause it to stretch or pull, and ultimately tear. When the process occurs on mattresses, the appearance is poor but most importantly, can create discomfort and problems with sleeping. The answer, unfortunately, is not merely to make the cushion of a firmer foam, because then comfort is sacrificed.
While considerable effort and some success has been achieved in inner spring type mattresses and cushions, to the knowledge of the applicant there has been no success in prior attempts to reinforce the corners and edges of foam mattresses or cushions to prevent the occurrence of rollover after periods of use.